Predictors of patient compliance during Class II division 1 malocclusion functional orthodontic treatment

Patient-centered factors associated with orthodontic treatment success: a scoping review

The aim of this systematic review was to synthesize the available literature on pretreatment factors, from a patient-centered perspective, that predict successful orthodontic treatment. Systematic and unrestricted searches were conducted across the electronic MEDLINE, Embase, Web-of-Science, Scopus, Cochrane Library, and LILACS/Bireme databases. Grey literature was also searched to identify potential studies. Qualitative assessments of the role of patient-centered pretreatment factors in orthodontic treatment success (adherence, satisfaction, and discontinuation rates) were evaluated and synthesized. Study selection and data extraction were performed independently by two reviewers. A total of sixteen studies were included. Three main domains related to the patient emerged as positive predictors of orthodontic treatment success: previous patterns of social behavior, attitudes of parents/caregivers, and reasonable motivation. Certain personality traits were associated with both positive and negative levels of adherence and treatment satisfaction. The evidence did not support the notion that the impact of malocclusion on aesthetic self-perception could serve as an indicator of cooperation, satisfaction, or discontinuation rates related to orthodontic treatment. Positive social behavior patterns and parental/caregiver attitudes, along with realistic prior motivation toward treatment goals, were found to be reliable predictors of orthodontic treatment success. Additionally, some personality traits were found to be associated with successful treatment outcomes. However, the evidence did not support the impact of malocclusion on self-perceived aesthetics as an indicator of compliance and satisfaction levels with orthodontic treatment.

Evaluating stress and displacement in the craniomandibular complex using Twin Block appliances at varied angles: A finite element study

OBJECTIVES

The objective of this investigation was to assess the stress and displacement pattern of the craniomandibular complex by employing finite element methodology to simulate diverse angulations of inclined planes that are incorporated in the Twin Block appliance.

METHODS

A 3D finite element representation was established by use of Cone Beam Computed Tomography (CBCT) scans. This comprehensive structure included craniofacial skeletal components, the articular disc, a posterior disc elastic layer, dental elements, periodontal ligaments, and a Twin Block appliance. This investigation is the first to incorporated inclined planes featuring three distinct angulations (45, 60, and 70°) as the study models. Mechanical impacts were evaluated within the glenoid fossa, tooth, condylar, and articular disc regions.

RESULTS

In all simulations, the stress generated by the Twin Block appliance was distributed across teeth and periodontal ligament, facilitating the anterior movement of mandibular teeth and the posterior displacement of maxillary teeth. Within the temporomandibular joint region, compressive forces on the superior and posterior facets of the condyle diminished, coinciding with the stress configuration that fosters condylar and mandibular growth. Stress dispersion homogenized in the condylar anterior facet and articular disc, with considerable tensile stress in the glenoid fossa's posterior aspect conforming to stress distribution that promote fossa reconfiguration. The 70° inclined plane exerts the highest force on the tissues. The condyle's maximum and minimum principal stresses are 0.36 MPa and -0.15 MPa, respectively, while those of the glenoid fossa are 0.54 MPa and -0.23 MPa.

CONCLUSION

Three angled appliances serve the purpose of advancing the mandible. A 45° inclined plane relative to the occlusal plane exerts balanced anteroposterior and vertical forces on the mandibular arch. Steeper angles yield greater horizontal forces, which may enhance forward growth and efficient repositioning.

New Solution in the Treatment of Children with Class II Malocclusion: Biblock Appliance

BACKGROUND

A new design, the Biblock appliance, was developed for the functional treatment of Class II malocclusions.

AIM

To compare the effects of Biblock appliance (BA) and Activator appliance (AA) on the skeleton, dentoalveolar, and soft tissue in Class II malocclusions.

METHODS

Thirty-five patients with mandibular retrognathia caused by skeletal Class II malocclusion and normodivergent growth pattern were included in this study. After selecting the BA group (n = 17, 8 boys and 9 girls, mean age = 12.08 ± 0.37 years), we selected the active control group treated with AA (n = 18, 9 boys and 9 girls, mean age = 12.3 ± 0.27 years), which matched the BA group's development and gender. All patients were between PP2 = DP3u periods according to hand-wrist maturation. Cephalometric variables related to the skeletal, dentoalveolar, and soft tissue were measured.

RESULTS

Treatment duration was 18.17 ± 1.45 months with BA and 16.92 ± 1.09 months with AA. Skeletal Class II malocclusion improved significantly in both groups. In the compared groups, the increase in ANS-Me was significantly higher in the AA group (P < 0.05). The Cd⊥SN and S-Cd increase in the compared groups was significantly higher in the BA group (P < 0.05). There was no significant difference in measurements between the groups in skeletal, dentoalveolar, and soft tissue measurements (P > 0.05).

CONCLUSION

The effects of AA, an appliance accepted by the orthodontic community, and BA, a new design, on the skeletal, dentoalveolar, and soft tissue were similar.

Patient adherence in orthodontics: a scoping review

BACKGROUND

Patient adherence is a key factor in achieving orthodontic treatment success. Despite an evolution in orthodontic healthcare, no recent comprehensive reviews are available on patient adherence in orthodontics. This scoping review provides an evidence-based overview of the literature available on multiple aspects of patient adherence in orthodontics, during both active treatment as well as during the retention phase. Knowledge gaps identified in the literature are listed.

METHODS

The protocol for this scoping review was registered in the Open Science Framework ( https://doi.org/10.17605/OSF.IO/EC6QD ). Electronic databases and reference lists of relevant studies were searched up to 9 February 2023. The inclusion criteria were studies investigating any form of patient adherence in orthodontics published in English from 2006 onwards. The exclusion criteria were studies investigating adherence in the following patients: those with an intellectual or physical disability that could affect their ability to coincide with their therapist's recommendations and advice, those with oral cleft and craniofacial conditions, and those treated solely for obstructive sleep apnoea. Non-peer-reviewed studies and case reports were also excluded.

RESULTS

A total of 3284 articles were identified, 60 of which met the criteria for final inclusion.

CONCLUSIONS

There is no conclusive evidence on which factors have a significant impact on patient adherence and how patient adherence can be promoted. The degree of patient adherence is generally not compared to achieved treatment results or stability of treatment results, making it difficult to provide clear statements about the impact of the degree of adherence on desired treatment results or orthodontic stability.

Long-term (≥ 15 years) outcome quality after Class II:1 bionator or Herbst multibracket appliance treatment : A comparison

PURPOSE

To compare the long-term outcome quality (≥ 15 years) of Class II:1 treatment using either a bionator (BIO) or a Herbst-multibracket appliance (HMB).

METHODS

Patients who underwent functional treatment during the ideal treatment period for the respective approach (prepuberty vs. peak/postpeak) were assessed. Inclusion criteria were overjet ≥ 4 mm, skeletal Class II and availability of study casts from before, after and ≥ 15 years after treatment. The study casts were assessed using the Peer Assessment Rating (PAR) index and standard orthodontic cast measurements.

RESULTS

During treatment, PAR score, overjet and sagittal occlusal relationship improved significantly in all groups. Long-term, there was a significant increase of incisor irregularity in the upper (HMB) and lower (BIO) arch and a significant decrease of lower arch width 3 - 3 (BIO). PAR score, overjet, and sagittal occlusal relationship remained stable long-term. Intergroup comparisons revealed significant differences between the BIO and HMB groups in terms of lower arch width (6 - 6), upper and lower arch width (3 + 3/3 - 3) as well as sagittal molar relationship.

CONCLUSIONS

The achieved improvement in PAR score, overjet, and sagittal occlusion remained comparably stable long-term in all groups. The long-term changes are probably a consequence of natural aging.

Three-dimensional Evaluation of the Carriere Motion 3D Appliance in the treatment of Class II malocclusion

INTRODUCTION

This study aimed to quantify the outcomes of adolescent patients with Class II malocclusion treated with the Carriere Motion 3D Appliance (CMA) combined with full fixed appliances.

METHODS

Cone-beam computed tomography scans of 22 patients were available before orthodontic treatment (T1), at removal of the CMA (T2), and posttreatment (T3). The average age of the patients was 13.5 ± 1.6 years at T1, 14.1 ± 0.2 years at T2, and 15.6 ± 0.5 years at T3. The 3-dimensional image analysis procedures were performed using ITK-SNAP (version 3.6.0; www.itksnap.org, Hatfield, Pa) and SlicerCMF (version 4.11.0; http://www.slicer.org, Cambridge, Mass); skeletal and dentoalveolar changes relative to cranial base, maxillary, and mandibular regional superimpositions were evaluated.

RESULTS

Changes were analyzed with 1 sample t tests using the mean differences during the CMA phase (T1 to T2) and total treatment time (T1 to T3). Significant skeletal changes included a slight reduction of ANB from T1 to T3, mandibular growth (Co-Gn increment of 1.2 mm and 3.3 mm from T1 to T2 and T1 to T3, respectively), inferior displacement of point A, and anterior and inferior displacement of point B. The mandibular plane did not change significantly during treatment. During the CMA treatment, posterior tipping and distal rotation of the maxillary molars, tip back and inferior displacement of the maxillary canines, significant mesial rotation, and superior displacement of the mandibular molars were observed. These movements rebounded during the full fixed appliance phase except for the molar and canine vertical displacements. Clinically significant dental changes during treatment included a reduction in overjet and overbite, Class II correction of the molar and canine relationship, and proclination of the mandibular incisors.

CONCLUSIONS

The CMA is an effective treatment modality for Class II correction in growing patients because of a combination of mesial movement of the mandibular molar, distal rotation of the maxillary molar, and anterior displacement of the mandible.

Stress distribution of the modified clear twin-block aligner on the temporomandibular joint, alveolar bone and teeth: A finite element analysis

OBJECTIVE

The modified clear twin-block aligner (CTBA) was developed to provide a mandibular advancement appliance for the treatment of mandibular retrognathia. The objective of this study was to analyse the stress distribution changes of CTBA with 45°, 60° and 70° bite blocks.

MATERIAL AND METHODS

A three-dimensional model of the craniomaxillofacial bones and teeth was generated from a spiral computed tomography (CT) scan. The models of the articular disc, capsule, periodontal ligament and CTBA were constructed mathematically. After assigning the appropriate material properties and the boundary condition using ABAQUS software, we simulated the CTBA with different bite blocks to analyse the mechanical effects.

RESULTS

In the temporomandibular joint (TMJ) region, the posterior aspect of the condyle and glenoid fossa experienced tensile stress that was approximately about 22 times greater at 70° than at 45°. The Von Mises stress distribution on the articular disc tended to be uniform. The strain direction of the condyle was backward. In the maxillary bone, the stress on the labial alveolar bone was about 5.83MPa at 70° and greater than that on the lingual side. The resulting displacement of the dentition revealed a tendency for the upper teeth to shift backward and the lower teeth to move forward by 0.46 to 0.49mm. The foregoing stress and displacement rose as the angle of the bite blocks increased.

CONCLUSIONS

CTBA with 70° bite blocks constituted an advantageous biomechanical setting for the treatment of mandibular retrognathia in teenagers and provided a superior therapeutic effect.

Comparison of masticatory myofunctional rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion. A retrospective cohort study

OBJECTIVE

To estimate the clinical efficacy of early masticatory myofunction rehabilitation combined with conventional functional appliances for the treatment of class Ⅱ, division 1 malocclusion in orthodontic children during the growing phase.

MATERIALS AND METHOD

A comparative retrospective cohort study, enrolled patients diagnosed with class Ⅱ/1 in the stage of late mixed or early permanent dentition. Patients were divided into a TBA group (Cohort 1): receiving Twin-block appliance treatment; and a MMR group (Cohort 2): receiving either early masticatory myofunction rehabilitation as adjunctive therapy combined with the same conventional functional appliances. The study variables were active (Phase 1) treatment duration, oral esthetic subjective impact score (OASIS), several cephalometric indices calculated from X-ray photographs, the maximum voltage (mV) and asymmetry index (AsI) of anterior temporalis (TA) and masseter muscles (MM) before and after treatment. Complications were also recorded.

RESULTS

A total of 424 cases were enrolled. The mean treatment duration in the MMR group was 168.33 days (SD: 25.43) and 215.00 days (SD: 28.81) in the TBA group; mean difference: -46.67 days (95% CI: [-81.62, -11.71]), P<0.001. For the OASIS outcome measure, there was no statistically significant difference between the mean total scores for the MMR group (18.83±7.73) or TBA group (17.67±6.47) groups adjusted to include pre-treatment OASIS scores (P = 0.783). After treatment, sella-nasion-B point (SNB), mandibular incisor angle, maxillary base and mandibular base in both two groups were significantly increased, while AB plane angle (ANB), maxillary incisor angle, overjet and overbite were significantly decreased. The mV and AsI of TA and MM were also improved following treatment. However, no significant differences were observed between two groups.

CONCLUSION

Our results confirmed that early masticatory myofunction rehabilitation in combination with conventional TBA for patients in the growing phase was significantly effective in the management of class Ⅱ/1 in orthodontic treatment, which could significantly shorten the treatment duration and had the similar improvement in the cephalometry data, OASIS scores and masticatory muscles function when comparing to conventional TBA alone.

The digital Twin Block appliance: Concept, design and fabrication

The Twin Block appliance (TBA) has evolved over the decades to remain a very effective treatment for growing Class II patients. This article introduces how two new versions of the TBA may be produced through an entirely digital workflow, from intra-oral scanning to thermoplastic appliance fabrication, using a novel computer-aided design process.